Daratumumab: The First Myeloma "Breakthrough Therapy"

I haven't been keeping up with my myeloma research in recent months, but I'm making up for lost time now.

In 2012, the Food and Drug Administration Safety and Innovation Act (FDASIA) was enacted. Section 902 created a new category of "breakthrough therapies" that the FDA is supposed to accelerate through its approval process, so that they can reach patients much sooner than would ordinarily be the case. These therapies must represent significant improvements over existing therapies in the treatment of serious or life-threatening conditions. Since at least some clinical evidence of improvement must be demonstrated in advance, the requirements for the "breakthrough" designation are more stringent than for the older alternative "fast track" designation, which can be granted based on preclinical evidence, if the therapy "fills an unmet medical need", i.e. there are no existing therapies at all. At least in theory, a breakthrough therapy could be released to patients after Phase 1 or 2 clinical trials.

In May 2013, the FDA designated daratumumab a breakthrough therapy against refractory myeloma, i.e. myeloma that has become resistant to the existing mainstream therapies, such as bortezomib and lenalidomide.

Phase 2 trials were announced earlier this month.

2013 Test Data

The most recent round of tests had mixed results. Monoclonal proteins continued their upward march, but Kappa free light chains declined. I am in the middle of only the second cycle of the increased 25mg Revlimid dosage, so we must give that time to work. Another UPEP test was also done; this failed to show enough protein concentration to allow UPEP evaluation, which is a good thing.

Here is a summary of the tests so far this year. Note that anything other than "None" is undesirable for the monoclonal proteins; the normal range for Kappa free light chains is 3.3 - 19.4 mg/L, and for the Kappa/Lambda ratio, it is 0.26 - 1.65.

Test Date	Monoclonal Spike (g/dL)	Kappa Free Light Chains (mg/L)	Kappa/Lambda Ratio
1/22/13	None	16.3	1.38
2/18/13	"Faint"	19.6	1.34
3/18/13	0.2	21.6	1.41
4/18/13	0.3	19.7	1.31
5/17/13	0.3	21.3	1.46
6/27/13	0.4	23.1	1.24
8/6/13	0.7	23.4	1.50
9/13/13	1.0	18.6	1.58